Apparatus and method for inspecting pattern

A pattern defect inspecting apparatus, comprising:

• a stage capable of placing a substrate to be inspected thereon and moving in X and Y directions;
• an ultraviolet laser light source for emitting ultraviolet laser light therefrom;
• an illumination optical system including a multispot shaper for forming a plurality of light-emitting images from the ultraviolet laser light emitted from said ultraviolet laser light source, a coherence reduction optical system for two-dimensionally scanning the ultraviolet laser light comprised of the plurality of light emitting images formed by the multispot shaper on a pupil of an objective lens to reduce coherence, and a converging optical system for allowing a plurality of pieces of the ultraviolet laser light reduced in coherence through said coherence reduction optical system to converge on a pupil position of an objective lens, said illumination optical system applying the plurality of pieces of ultraviolet laser light focused on the pupil of the objective lens by said converging optical system onto the substrate to be inspected;
• a detection optical system including an image forming optical system for focusing an ultraviolet reflected light image from a circuit pattern formed on the substrate to be inspected, and an image sensor for receiving the ultraviolet reflected light image focused by the image forming optical system and converting the same into an image signal;
• and
• an image signal processing circuit including an A/D converter for A/D converting the image signal obtained from the image sensor of said detection optical system, and a comparator for comparing a detected digital image signal converted by the A/D converter with a reference digital image signal to thereby detect a defect or a defect candidate in the circuit pattern and outputting inspection information in relation to the defect or the defect candidate.

A pattern defect inspecting apparatus, comprising:

• a stage capable of placing a substrate to be inspected thereon and moving in X and Y directions;
• an ultraviolet laser light source for emitting ultraviolet laser light therefrom;
• an illumination optical system including a multispot shaper for forming a plurality of light-emitting images from the ultraviolet laser light emitted from said ultraviolet laser light source, a coherence reduction optical system which installs therein at least one swinging first optical device or at least one rotating second optical device so as to reduce coherence with respect to the ultraviolet laser light comprised of the plurality of light emitting images formed by the multispot shaper, and a converging optical system for allowing a plurality of pieces of the ultraviolet laser light reduced in coherence through said coherence reduction optical system to converge on a pupil position of an objective lens, said illumination optical system applying the plurality of pieces of ultraviolet laser light focused on the pupil of the objective lens by said converging optical system onto the substrate to be inspected;
• a detection optical system including an image forming optical system for focusing an ultraviolet reflected light image from a circuit pattern formed on the substrate to be inspected, and an image sensor for receiving the ultraviolet reflected light image focused by the image forming optical system and converting the same into an image signal;
• and
• an image signal processing circuit including an A/D converter for A/D converting the image signal obtained from the image sensor of said detection optical system, and a comparator for comparing a detected digital image signal converted by the A/D converter with a reference digital image signal to thereby detect a defect or a defect candidate in the circuit pattern and outputting inspection information in relation to the defect or the defect candidate.

A pattern defect inspecting apparatus, comprising:

• a stage capable of placing a substrate to be inspected thereon and moving in X and Y directions;
• an ultraviolet laser light source for emitting ultraviolet laser light therefrom;
• an illumination optical system including a multispot shaper for forming a plurality of light-emitting points from the ultraviolet laser light emitted from said ultraviolet laser light source, a coherence reduction optical system configured so as to place at least one swinging first optical device and at least one rotating second optical device at positions unconjugated with respect to each other for reducing coherence with respect to the ultraviolet laser light comprised of the plurality of light emitting points formed by the multispot shaper, and a converging optical system for allowing a plurality of pieces of the ultraviolet laser light reduced in coherence through said coherence reduction optical system to converge on a pupil position of an objective lens, said illumination optical system applying the plurality of pieces of ultraviolet laser light focused on the pupil of the objective lens by said converging optical system onto the substrate to be inspected;
• a detection optical system including an image forming optical system for focusing an ultraviolet reflected light image from a circuit pattern formed on the substrate to be inspected, and an image sensor for receiving the ultraviolet reflected light image focused by the image forming optical system and converting the same into an image signal;
• and
• an image signal processing circuit including an A/D converter for A/D converting the image signal obtained from the image sensor of said detection optical system, and a comparator for comparing a detected digital image signal converted by the A/D converter with a reference digital image signal to thereby detect a defect or a defect candidate in the circuit pattern and outputting inspection information in relation to the defect or the defect candidate.

A pattern defect inspection method, comprising the following steps:

• an illuminating step for causing a multispot shaper to form a plurality of light-emitting images from ultraviolet laser light emitted from an ultraviolet laser light source, allowing a coherence reduction optical system to reduce coherence with respect to the ultraviolet laser light comprised of the formed plural light-emitting images, and allowing a converging optical system to gather a plurality of pieces of the ultraviolet laser light reduced in coherence at a pupil position of an objective lens and apply the gathered plural pieces of ultraviolet laser light onto a substrate to be inspected;
• a detecting step for allowing an image forming optical system to focus an ultraviolet reflected light image from a circuit pattern formed on the substrate irradiated by said illuminating step, and causing an image sensor to receive the focused ultraviolet reflected light image and to convert the same into an image signal;
• an image signal processing step for A/D converting the image signal obtained from the image sensor in said detecting step, comparing the A/D-converted detected digital image signal with a reference digital image signal to thereby detect a defect or a defect candidate in the circuit pattern and outputting inspection information;
• and
• an amount-of-light monitoring step for allowing some of the ultraviolet laser light emitted from the ultraviolet laser light source to branch and monitoring the intensity thereof.

A pattern defect inspecting method, comprising the following steps:

• an illuminating step for causing a multispot shaper to form a plurality of light-emitting images from ultraviolet laser light emitted from an ultraviolet laser light source, allowing a coherence reduction optical system to two-dimensionally scan the ultraviolet laser light comprised of the formed plural light-emitting images on a pupil of an objective lens to thereby reduce coherence, and allowing a converging optical system to gather a plurality of pieces of the ultraviolet laser light reduced in coherence at a pupil position of an objective lens and apply the gathered plural pieces of ultraviolet laser light onto a substrate to be inspected;
• a detecting step for allowing an image forming optical system to focus an ultraviolet reflected light image from a circuit pattern formed on the substrate irradiated by said illuminating step, and causing an image sensor to receive the focused ultraviolet reflected light image and convert the same into an image signal;
• and
• an image signal processing step for A/D converting the image signal obtained from the image sensor in said detecting step, comparing the A/D-converted detected digital image signal with a reference digital image signal to thereby detect a defect or a defect candidate in the circuit pattern and outputting inspection information in relation to the defect or the defect candidate.